I recently resolved an error with the SQL Server 2005 Configuration Manager.  Occasionally, during setup, some .mof files don't get installed and registered correctly.  There is a program called mofcomp that is responsible for registering and storing the data associated with .mof files.  If the .mof file information becomes damaged or compromised, or never installed correctly, the problem will result in an error message like below:

Cannot connect to WMI provider. You do not have permission or the server is unreachable. Note that you can only manage SQL Server 2005 servers with SQL Server Configuration Manager.
Invalid class [0x80041010]

The solution is to go to a command prompt and then run mofcomp.

C:\Program Files\Microsoft SQL Server\90\Shared>mofcomp "C:\Program Files\Microsoft SQL Server\90\Shared\sqlmgmproviderxpsp2up.mof"

The output will look like below


Microsoft (R) 32-bit MOF Compiler Version 5.1.2600.2180
Copyright (c) Microsoft Corp. 1997-2001. All rights reserved.
Parsing MOF file: C:\Program Files\Microsoft SQL Server\90\Shared\sqlmgmprovider
xpsp2up.mof
MOF file has been successfully parsed
Storing data in the repository...
Done!

On servers, the .mof file will be sqlmgmprovider.mof.